Illuminating devices with color stable thermoplastic light transmitting articles

ABSTRACT

Illuminating devices are disclosed having plastic light-transmitting article(s) formed from a thermoplastic composition including a polycarbonate having repeating structural carbonate units according to the formula: 
     
       
         
         
             
             
         
       
     
     in which at least 60 percent of the total number of R 1  groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic. The composition also includes an epoxy additive having at least two epoxy groups per molecule and a phenolic diphosphite derived from pentaerythritol. The thermoplastic composition exhibits a dE (2000 hrs.) value of less than 1.5 after 2000 hours of heat aging at 130° C., measured according ISO 11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mm thick molded plaque of the thermoplastic composition.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Non-Provisional and claims the benefit ofU.S. Provisional Application No. 61/828,413, filed on May 29, 2013, andalso claims the benefit of U.S. Provisional Application No. 61/972,074,filed Mar. 28, 2014, the contents of which are incorporated herein intheir entirety by reference.

BACKGROUND OF THE INVENTION

This disclosure relates to polycarbonate compositions and in particularto polycarbonate compositions having enhanced optical properties,methods of manufacture, and uses thereof.

Polycarbonates can provide a number of beneficial properties, and areused in the manufacture of articles and components for a wide range ofapplications, from automotive parts to electronic appliances.Polycarbonates, however, can undergo changes in their light absorbingand/or transmitting properties when they age, especially under theinfluence of heat and/or light exposure, resulting in reduced lighttransmission and/or color changes. Specifically, polycarbonates candevelop a yellowish tint and become darker when processed into anarticle and when aged under the influence of heat and/or light.

There accordingly remains a need in the art for polycarbonatecompositions that can provide desirable light absorbing and/ortransmitting properties under various aging conditions, includingpolycarbonate compositions that have low yellowness and high lighttransmission when processed into an article (e.g. through injectionmolding) and when aged (e.g. at higher temperature or for a long time).

It is well known that certain additives can improve the colorcharacteristics of virgin polycarbonate. Primary antioxidants such ashindered phenols can be added to polycarbonates to reduce discolorationof the formed articles during aging. These additives protect thematerial in the solid state against discoloration over time. Secondaryantioxidants such as phosphites can protect the material during hightemperature processing in the molten state such as with injectionmolding, leading to a better color of the formed article. These twotypes of antioxidants can be combined to optimize both the color of thearticle after formation as well as during its lifetime; however, thiscombination may not be effective to achieve desired discolorationperformance in various applications such as long-pathlength lightingapplications such as thick lenses, light guides etc. Although certainsecondary antioxidants, e.g. those based on pentaerythriol, can beeffective during molding, they reduce the longer term color stabilityand therefore cannot be added at high level.

Multifunctional epoxides can be used as additives for polymeric resinswith the aim of increasing viscosity, improving hydrolytic stability andrecyclability. However, for many polycarbonate compositions such asthose having a free hydroxy content of greater than 150 ppm and/orprepared from a bisphenol having a sulfur content of greater than 2 ppmby weight, the epoxy additive can actually increase the yellowness ofmolded article.

EP 0 320 658 A1 indicates that a pentaerythrol based phosphitestabilizer is useful as a process stabilizer for polycarbonatecompositions, but does not study the effect of (heat) aging. The patentindicates epoxy additives should not be added to the composition.

EP 0 885 929 A1 discloses compositions containing pentaerythrol baseddiphosphites and epoxy additives with the aim of improvingprocessability, reducing splay and improving hydrolytic stability. Noheat aging is investigated. BPA organic purity higher than 99.7% and/orrestrictions to the hydroxyl content in the BPA used to make thepolycarbonate are not being described.

U.S. Pat. No. 4,076,686 discloses polycarbonate compositions containingepoxy and phosphites indicating and advantage when replacing a dialkylhydrogen phosphite partly with an epoxy additive. The advantage that isshown in color stability is small and appears to be due to the loweringof the phosphite level.

U.S. Pat. No. 7,297,381 discloses polycarbonate compositions containingepoxy and phosphite for light-diffusing films and articles. Thesematerials contain light diffusing particles which render them unsuitablefor use in lenses, light guides, display panels and other applicationsin which transparency is key.

US2013/0035441A1 discloses interfacially polymerized transparentpolycarbonates where the polycarbonate has lower than 150 ppm hydroxylgroups and less than 2 ppm sulfur compounds with advantageous opticalproperties such as low starting color and good color stability in heataging. US2013/0108820A1 discloses a process to make BPA andpolycarbonate having a reduced sulfur content as well as containers madeof such polycarbonate. Polycarbonates made according to these inventionsexhibit improved color stability over other polycarbonates, but for longlight path length applications or applications involving close proximityto light sources, further improvement is desired.

In spite of the advances described in the above references, thereremains a need to achieve further improvements in starting color andcolor stability of polycarbonates for use in light-transmittingapplications.

SUMMARY OF THE INVENTION

It has now been discovered that polycarbonate compositions as furtherdescribed herein can provide enhanced optical qualities forlight-transmitting articles in illuminating devices comprising a lightsource and the light-transmitting article.

In an embodiment, an illuminating device, comprises: a light source; anda light-transmitting article formed from a thermoplastic composition,positioned to provide a light transmission path from the light sourcethrough the light-transmitting article, with a distance, d, between thelight source and the light-transmitting article of less than 40 mm, thelight transmission path extending through the light-transmitting articleand optionally through other light-transmitting article(s) comprisingthe thermoplastic composition such that the total distance, p, of thelight transmission path through the light-transmitting article is atleast 3 mm; wherein the thermoplastic composition comprises apolycarbonate having repeating structural carbonate units according tothe formula

in which at least 60 percent of the total number of R¹ groups containaromatic moieties and the balance thereof are aliphatic, alicyclic, oraromatic; the polycarbonate having been prepared through an interfacialpolymerization process from BPA monomer having an organic purity higherthan 99.70% by weight and having a hydroxyl content lower than 150 ppmby weight; 0.01 wt. % to 0.30 wt. %, based on the total weight of thethermoplastic composition, of an epoxy additive having at least twoepoxy groups per molecule; and 0.01 wt. % to 0.30 wt. %, based on thetotal weight of the thermoplastic composition, of a phenolic diphosphitederived from pentaerythritol; wherein the thermoplastic composition hasa sulfur content lower than 2 ppm, and wherein the thermoplasticcomposition exhibits a dE (2000 hrs.) value of less than 2.0 after 2000hours of heat aging at 130° C., measured according ISO11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mmthick molded plaque of the thermoplastic composition.

In an embodiment, a method of using the device, comprises illuminatingthe light-transmitting article with the light source under conditions tosubject the light-transmitting article to a temperature of 80° C. to135° C.

In an embodiment, a method for making the illuminating device,comprises: disposing the light source the distance d of less than 40 mmfrom the light-transmitting plastic article such that the totaldistance, p, of the light transmission path is at least 3 mm.

The above described and other features are further described by thefollowing figures and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features, and advantages of the invention aredescribed in the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a schematic depiction of an exemplary illuminating device asdescribed herein;

FIG. 2A is a schematic depiction of another exemplary illuminatingdevice as described herein;

FIG. 2B is an exploded view of a portion of the illuminating device ofFIG. 2A illustrating the light guide surface comprising an embodiment ofan optical grating structure; and

FIGS. 3 and 4 are plots of dE (2000 hrs.) values for test plaques of athermoplastic composition described herein.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the Figures, FIG. 1 depicts an illuminating device 10with a housing 12 (e.g., which can optionally comprising a reflectivesurface on its inner surface) around a light source 14 disposed therein.A light-transmitting article in the form of inner lens 16 is disposed ata distance, d, away from the light source. A second light-transmittingarticle in the form of outer lens 18 is disposed further away from thelight source 14 than the inner lens 16. In operation, light (the pathsof which are represented by arrowed dashed lines) is emitted from thelight source 14 and travels through and is refracted by the inner lens16 and the outer lens 18 where it is emitted from the illuminatingdevice 10.

FIG. 2A depicts an illuminating device 20 with a housing 22 having alight source 24 disposed therein. A first light-transmitting article inthe form of light guide 26 is disposed at a distance, d, from the lightsource 24. A second light-transmitting article in the form of lens 28 isdisposed on one side of the light guide 26. In operation, light (thepaths of which are represented by arrowed dashed lines) is emitted fromthe light source 24 and enters the light guide 26 through surface 30.The light guide is constructed and configured with the light source 24such that the light's angle of incidence with respect to the normal axisof the smooth surfaces 32 and 34 is greater than the critical angle ofthe polycarbonate composition in the surrounding medium (e.g., air) sothat light is internally reflected back into light guide 26 along thesurfaces 32 and 34 as it promulgates through the light guide 26. Surface39 can allow light to escape, or it can have a reflective coating toreflect light back into the interior of the light guide 26. At positions36 and 38 along the light guide surface 32, the normally smooth surface32 is instead configured with a sawtooth or other optical gratingstructure as shown in blowup view to the right. (See FIG. 2B) Internallypropagating light impinging on the surface 32 at positions 36 and 38 isable to exit the light guide 26 from where it travels through the lens28 where it is emitted from the illuminating device 20.

As mentioned above, the invention is directed to illuminating deviceswhere the distance, d, between a light source and a light-transmittingarticle is less than 40 mm. However, the composition described hereinalso excels in more demanding environments where light-transmittingarticle is in even closer proximity to the light source. Accordingly, insome embodiments, the distance between the light source and thelight-transmitting article is less than 20 mm. In some embodiments, thedistance is less than 10 mm. In some embodiments, the distance is lessthan 5 mm. In some embodiments, d is effectively 0 where thelight-transmitting article is in direct contact with the light source ora protective cover thereon.

As mentioned above, disclosed herein are illuminating devices (alsoreferred to as a light-emitting device) where the light transmissionpath extending through the light-transmitting article and optionallythrough other light-transmitting article(s) comprising the polycarbonatecomposition such that the total distance, p, of the light transmissionpath through the light-transmitting article(s) is at least 3 mm.However, the composition described herein also excels in more demandingenvironments where even longer light-transmission paths through thelight-transmitting article(s) are contemplated. Accordingly, in someembodiments, the light transmission path distance through thelight-transmitting article(s) is at least 5 mm. In some embodiments, thelight transmission path distance through the light-transmittingarticle(s) is at least 7 mm. In some embodiments, the light transmissionpath distance through the light-transmitting article(s) is at least 10mm. In some embodiments, the light transmission path distance throughthe light-transmitting article(s) is at least 20 mm.

Several representative light paths are indicated in FIGS. 1 and 2A usingdotted lines. The light path, defined as the total linear distancethrough the material that light passes before leaving the object isindicated with p1 and p2 in FIG. 1, and with p3 and p4 in FIG. 2A. Thetotal light path p is the sum of the light paths through individualcomponents. Note that in the case of a light guide as shown in FIG. 2A,the path p4 can be shorter than the length of the guide (for lightexiting the object earlier) but also longer than the length of the guide(through multiple internal reflections). Hence, light path p will be adistribution rather than a fixed number. As used herein, the length p ofthe light transmission path through the polycarbonate composition meansthe average of such distribution. The average light path length p can bereadily calculated using known mathematical techniques by plotting theangle of incidence for all light exiting the illuminating device versusthe light path length and then calculating an average of thedistribution of light path lengths.

Of course, FIGS. 1 and 2A are exemplary in nature and are shown inrelatively simple configurations to illustrate the principals involved.Practical designs for light-transmitting articles can have a highercomplexity for applications such as an illuminant lens (e.g., acollimator lens), illuminant cover, a light guide (also known as anoptical waveguide) (e.g., an optical fiber), an optical sheet (e.g., atransparent sheet, a display film, and so forth). The illuminatingdevice which comprises the light-transmitting article can be any devicethat is lighted, such as a toy (e.g., a light sword, light saber, and soforth), an illuminant article of furniture (e.g., a lighted table,lighted chair, bar, etc. with light illuminating features therein), artobject, a light (e.g., a lamp (e.g. motor vehicle headlamp, house lamp,security lamp, and so forth) and so forth. For example, thelight-emitting device is a motor vehicle headlamp such as shown in FIGS.1 and 2A. The light-transmitting article can be disposed within aninternally reflective housing that directs light through a transparentfront cover. Limited space requirements commonly found in automotiveheadlamps and other automotive lighting applications can necessitateconfigurations where the close-coupled light source and/or long lighttravel path benefits can be especially effective.

Illuminating devices using polycarbonate compositions described hereincan be used in connection with other illuminating features of variousmaterials such as multiple light sources, lenses, light guides,reflectors, covers and other light-modifying components. Lenses can bespherical or aspheric. Aspheric lenses can have significantly greaterthickness variations than spherical lenses because the distance from thefocal point to the lens edge is not constant as with a spherical lens,rendering aspheric lenses particularly susceptible to color variation orinstability in the lens material. Accordingly, in some embodiments, thelight-transmitting article is an aspheric lens.

The light source such as the light source 14, 24 in FIGS. 1 and 2A canbe any type of light source. In some embodiments, the light source is anLED. Many LED's require a cover, lens, or other light-transmittingarticle in close proximity to the LED. Accordingly, in some embodiments,the light source is an LED disposed within any of the d distance valuesspecified above with respect to the light-transmitting article (i.e., 20mm, 10 mm, 5 mm or 0 mm). In some embodiments, the light source is axenon arc or other light source of similar whiteness, where the opticalproperties and stability of the polycarbonates described are effectivelyutilized.

The polycarbonate used in the light-transmitting articles describedherein has defined optical properties of a dE (2000 hrs.) value of lessthan 2.0, more specifically less than 1.5, and even more specificallyless than 0.95 after 2000 hours of heat aging at 130° C., with the dEcalculation based on a comparison between an un-aged sample and a samplesubjected to 2000 hours of heat aging at 130° C., measured according ISO11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mmthick molded plaque of the thermoplastic composition. The colorstability indicated by the above-described dE (2000 hrs.) values can bebeneficial for compositions having an initial color that can bedescribed by various CIELAB color space values, as specified by ISO11664-4:2008(E)/CIE S 014-4/E:2007. With initial color, or startingcolor is meant the color of a molded plaque short after molding, beforeany aging (thermal, light) has taken place which might change the colorof the plaque. In some exemplary embodiments, the thermoplastic exhibitsCIELAB 1976 color space values of b*<0.56 and L*>95.65, measuredaccording to ISO 11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminantD65 and a 2.5 mm thick molded plaque of the thermoplastic composition.In some exemplary embodiments, the thermoplastic exhibits CIELAB 1976color space values of b*<0.54 and L*>95.75, determined as describedabove. In some exemplary embodiments, the thermoplastic exhibits CIELAB1976 color space values of b*<0.52 and L*>95.85, determined as describedabove. Unless otherwise specified, the dE (2000 hrs.) value and theCIELAB 1976 color space values, are all determined based on colormeasurements made using a Macbeth 7000A spectrophotometer with a D65illuminant, 10° observer, in transmission mode, specular included,ultraviolet component excluded, and both lens and aperture set to large,where dE is calculated according to dE1976

As mentioned above, the thermoplastic composition includes apolycarbonate. A “polycarbonate” means compositions having repeatingstructural carbonate units of formula (1)

in which at least 60 percent of the total number of R¹ groups containaromatic moieties and the balance thereof are aliphatic, alicyclic, oraromatic. The polycarbonate is prepared through an interfacialpolymerization process from BPA monomer of an organic purity higher than99.70% w and having a hydroxyl content lower than 150 ppm. In someembodiments, each R¹ is a C₆₋₃₀ aromatic group, that is, contains atleast one aromatic moiety. R¹ can be derived from a dihydroxy compoundof the formula HO—R¹—OH, in particular of formula (2)

HO-A¹-Y¹-A²-OH  (2)

wherein each of A¹ and A² is a monocyclic divalent aromatic group and Y¹is a single bond or a bridging group having one or more atoms thatseparate A¹ from A². In some embodiments, one atom separates A¹ from A².Specifically, each R¹ can be derived from a dihydroxy aromatic compoundof formula (3)

wherein R^(a) and R^(b) are each independently a halogen, C₁₋₁₂ alkoxy,or C₁₋₁₂ alkyl; and p and q are each independently integers of 0 to 4.It will be understood that R^(a) is hydrogen when p is 0, and likewiseR^(b) is hydrogen when q is 0. Also in formula (3), X^(a) is a bridginggroup connecting the two hydroxy-substituted aromatic groups, where thebridging group and the hydroxy substituent of each C₆ arylene group aredisposed ortho, meta, or para (specifically para) to each other on theC₆ arylene group. In some embodiments, the bridging group X^(a) issingle bond, —O—, —S—, —S(O)—, —S(O)₂—, —C(O)—, or a C₁₋₁₈ organicgroup. The C₁₋₁₈ organic bridging group can be cyclic or acyclic,aromatic or non-aromatic, and can further comprise heteroatoms such ashalogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. The C₁₋₁₈organic group can be disposed such that the C₆ arylene groups connectedthereto are each connected to a common alkylidene carbon or to differentcarbons of the C₁₋₁₈ organic bridging group. In an embodiment, p and qis each 1, and R^(a) and R^(b) are each a C₁₋₃ alkyl group, specificallymethyl, disposed meta to the hydroxy group on each arylene group.

In some embodiments, X^(a) is a substituted or unsubstituted C₃₋₁₈cycloalkylidene, a C₁₋₂₅ alkylidene of formula —C(R^(c))(R^(d))— whereinR^(c) and R^(d) are each independently hydrogen, C₁₋₁₂ alkyl, C₁₋₁₂cycloalkyl, C₇₋₁₂ arylalkyl, C₁₋₁₂ heteroalkyl, or cyclic C₇₋₁₂heteroarylalkyl, or a group of the formula —C(═R^(e))— wherein R^(e) isa divalent C₁₋₁₂ hydrocarbon group. Groups of this type includemethylene, cyclohexylmethylene, ethylidene, neopentylidene, andisopropylidene, as well as 2-[2.2.1]-bicycloheptylidene,cyclohexylidene, cyclopentylidene, cyclododecylidene, andadamantylidene.

In some embodiments, X^(a) can be a C₁₋₁₈ alkylene group, a C₃₋₁₈cycloalkylene group, a fused C₆₋₁₈ cycloalkylene group, or a group ofthe formula —B¹-G-B²— wherein B¹ and B² are the same or different C₁₋₆alkylene group and G is a C₃₋₁₂ cycloalkylidene group or a C₆₋₁₆ arylenegroup. For example, X^(a) can be a substituted C₃₋₁₈ cycloalkylidene offormula (4)

wherein R^(r), R^(p), R^(q), and R^(t) are each independently hydrogen,halogen, oxygen, or C₁₋₁₂ hydrocarbon groups; Q is a direct bond, acarbon, or a divalent oxygen, sulfur, or —N(Z)— where Z is hydrogen,halogen, hydroxy, C₁₋₁₂ alkyl, C₁₋₁₂ alkoxy, or C₁₋₁₂ acyl; r is 0 to 2,t is 1 or 2, q is 0 or 1, and k is 0 to 3, with the proviso that atleast two of R^(r), R^(p), R^(q), and R^(t) taken together are a fusedcycloaliphatic, aromatic, or heteroaromatic ring. It will be understoodthat where the fused ring is aromatic, the ring as shown in formula (4)will have an unsaturated carbon-carbon linkage where the ring is fused.When k is one and i is 0, the ring as shown in formula (4) contains 4carbon atoms, when k is 2, the ring as shown in formula (4) contains 5carbon atoms, and when k is 3, the ring contains 6 carbon atoms. In anembodiment, two adjacent groups (e.g., R^(q) and R^(t) taken together)form an aromatic group, and in another embodiment, R^(q) and R^(t) takentogether form one aromatic group and R^(r) and R^(p) taken together forma second aromatic group. When R^(q) and R^(t) taken together form anaromatic group, R^(p) can be a double-bonded oxygen atom, i.e., aketone.

Bisphenols (4) can be used in the manufacture of polycarbonatescontaining phthalimidine carbonate units of formula (4a)

wherein R^(a), R^(b), p, and q are as in formula (4), R³ is eachindependently a C₁₋₆ alkyl group, j is 0 to 4, and R₄ is a C₁₋₆ alkyl,phenyl, or phenyl substituted with up to five C₁₋₆ alkyl groups. Inparticular, the phthalimidine carbonate units are of formula (4b)

wherein R⁵ is hydrogen or a C₁₋₆ alkyl. In an embodiment, R⁵ ishydrogen. Carbonate units (4a) wherein R⁵ is hydrogen can be derivedfrom 2-phenyl-3,3′-bis(4-hydroxy phenyl)phthalimidine (also known asN-phenyl phenolphthalein bisphenol, or “PPPBP”) (also known as3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-1-one).

Other bisphenol carbonate repeating units of this type are theisatin-derived carbonate units of formula (4c) and (4d)

wherein R^(a) and R^(b) are each independently C₁₋₁₂ alkyl, p and q areeach independently 0 to 4, and R^(i) is C₁₋₁₂ alkyl, phenyl, optionallysubstituted with 1 5 to C₁₋₁₀ alkyl, or benzyl optionally substitutedwith 1 to 5 C₁₋₁₀ alkyl. In an embodiment, R^(a) and R^(b) are eachmethyl, p and q are each independently 0 or 1, and R^(i) is C₁₋₄ alkylor phenyl.

Examples of bisphenol carbonate units derived from bisphenols (4)wherein X^(a) is a substituted or unsubstituted C₃₋₁₈ cycloalkylideneinclude the cyclohexylidene-bridged, alkyl-substituted bisphenol offormula (4e)

wherein R^(a) and R^(b) are each independently C₁₋₁₂ alkyl, R^(g) isC₁₋₁₂ alkyl, p and q are each independently 0 to 4, and t is 0 to 10. Ina specific embodiment, at least one of each of R^(a) and R^(b) aredisposed meta to the cyclohexylidene bridging group. In an embodiment,R^(a) and R^(b) are each independently C₁₋₄ alkyl, R^(g) is C₁₋₄ alkyl,p and q are each 0 or 1, and t is 0 to 5. In another specificembodiment, R^(a), R^(b), and R^(g) are each methyl, r and s are each 0or 1, and t is 0 or 3, specifically 0. For example,

Examples of other bisphenol carbonate units derived from bisphenol (4)wherein X^(a) is a substituted or unsubstituted C₃₋₁₈ cycloalkylideneinclude units (4f) (also known as adamantyl units) and units (4g)

wherein R^(a) and R^(b) are each independently C₁₋₁₂ alkyl, and p and qare each independently 1 to 4. In a specific embodiment, at least one ofeach of R^(a) and R^(b) are disposed meta to the cycloalkylidenebridging group. In an embodiment, R^(a) and R^(b) are each independentlyC₁₋₃ alkyl, and p and q are each 0 or 1. In another specific embodiment,R^(a), R^(b) are each methyl, p and q are each 0 or 1. Carbonatescontaining units (4a) to (4g) are useful for making polycarbonates withhigh glass transition temperatures (Tg) and high heat distortiontemperatures.

Other useful aromatic dihydroxy compounds of the formula HO—R¹—OHinclude compounds of formula (6)

wherein each R^(h) is independently a halogen atom, a C₁₋₁₀ hydrocarbylsuch as a C₁₋₁₀ alkyl group, a halogen-substituted C₁₋₁₀ alkyl group, aC₆₋₁₀ aryl group, or a halogen-substituted C₆₋₁₀ aryl group, and n is 0to 4. The halogen is usually bromine.

Some illustrative examples of specific aromatic dihydroxy compoundsinclude the following: 4,4′-dihydroxybiphenyl, 1,6-dihydroxynaphthalene,2,6-dihydroxynaphthalene, bis(4-hydroxyphenyl)methane,bis(4-hydroxyphenyl)diphenylmethane,bis(4-hydroxyphenyl)-1-naphthylmethane, 1,2-bis(4-hydroxyphenyl)ethane,1,1-bis(4-hydroxyphenyl)-1-phenylethane,2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane,bis(4-hydroxyphenyl)phenylmethane,2,2-bis(4-hydroxy-3-bromophenyl)propane,1,1-bis(hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane,1,1-bis(4-hydroxyphenyl)isobutene,1,1-bis(4-hydroxyphenyl)cyclododecane,trans-2,3-bis(4-hydroxyphenyl)-2-butene,2,2-bis(4-hydroxyphenyl)adamantane, alpha,alpha′-bis(4-hydroxyphenyl)toluene, bis(4-hydroxyphenyl)acetonitrile,2,2-bis(3-methyl-4-hydroxyphenyl)propane,2,2-bis(3-ethyl-4-hydroxyphenyl)propane,2,2-bis(3-n-propyl-4-hydroxyphenyl)propane,2,2-bis(3-isopropyl-4-hydroxyphenyl)propane,2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane,2,2-bis(3-t-butyl-4-hydroxyphenyl)propane,2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,2,2-bis(3-allyl-4-hydroxyphenyl)propane,2,2-bis(3-methoxy-4-hydroxyphenyl)propane,2,2-bis(4-hydroxyphenyl)hexafluoropropane,1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene,1,1-dibromo-2,2-bis(4-hydroxyphenyl)ethylene,1,1-dichloro-2,2-bis(5-phenoxy-4-hydroxyphenyl)ethylene,4,4′-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone,1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, ethylene glycolbis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether,bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide,bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorine,2,7-dihydroxypyrene,6,6′-dihydroxy-3,3,3′,3′-tetramethylspiro(bis)indane (“spirobiindanebisphenol”), 3,3-bis(4-hydroxyphenyl)phthalimide,2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene,2,7-dihydroxyphenoxathin, 2,7-dihydroxy-9,10-dimethylphenazine,3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and2,7-dihydroxycarbazole, resorcinol, substituted resorcinol compoundssuch as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl resorcinol,5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl resorcinol, 5-cumylresorcinol, 2,4,5,6-tetrafluoro resorcinol, 2,4,5,6-tetrabromoresorcinol, or the like; catechol; hydroquinone; substitutedhydroquinones such as 2-methyl hydroquinone, 2-ethyl hydroquinone,2-propyl hydroquinone, 2-butyl hydroquinone, 2-t-butyl hydroquinone,2-phenyl hydroquinone, 2-cumyl hydroquinone, 2,3,5,6-tetramethylhydroquinone, 2,3,5,6-tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluorohydroquinone, 2,3,5,6-tetrabromo hydroquinone, or the like, orcombinations comprising at least one of the foregoing dihydroxycompounds.

Specific examples of bisphenol compounds of formula (3) include1,1-bis(4-hydroxyphenyl) methane, 1,1-bis(4-hydroxyphenyl) ethane,2,2-bis(4-hydroxyphenyl) propane (hereinafter “bisphenol A” or “BPA”),2,2-bis(4-hydroxyphenyl) butane, 2,2-bis(4-hydroxyphenyl) octane,1,1-bis(4-hydroxyphenyl) propane, 1,1-bis(4-hydroxyphenyl) n-butane,2,2-bis(4-hydroxy-2-methylphenyl) propane,1,1-bis(4-hydroxy-t-butylphenyl) propane, 3,3-bis(4-hydroxyphenyl)phthalimidine, 2-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine (PPPBP),and 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (DMBPC). Combinationscomprising at least one of the foregoing dihydroxy compounds can also beused. In one specific embodiment, the polycarbonate is a linearhomopolymer derived from bisphenol A, in which each of A¹ and A² isp-phenylene and Y¹ is isopropylidene in formula (3).

In some embodiments, the polycarbonate is derived from a bisphenol suchas bisphenol A. For example, at least 90% of the R1 groups in formula(1) can be derived from a bisphenol such as bisphenol A. In someembodiments, all of the R1 groups are derived from a bisphenol such asbisphenol A. In more specific embodiments, the bisphenol has a sulfurcontent and/or a free hydroxyl group content as described in US2013/0035441 A1 and US 2013/0108820 A1, the disclosures of which areincorporated herein by reference in their entirety. In some exemplaryembodiments, the bisphenol has less than or equal to 150 ppm by weightfree hydroxyl groups, based on the weight of the bisphenol. In someexemplary embodiments, the bisphenol comprises less than 2 ppm by weightsulfur, based on the weight of the bisphenol. In some exemplaryembodiments the bisphenol comprises from greater than 0 to 2 ppm, e.g.,0.5 ppm to 2 ppm by weight sulfur, and in some exemplary embodiments thebisphenol comprises less than 0.5 ppm by weight sulfur, based on theweight of the bisphenol.

In some embodiments, the above-described bisphenol sulfur levels can beachieved using the melt crystal purification techniques described in theabove-referenced US 2013/0108820A1. In some exemplary embodiments, amethod of making a purified bisphenol comprises reacting phenol withacetone in the presence of a sulfur containing promoter to obtain areaction mixture comprising a bisphenol such as bisphenol A, phenol, andthe promoter, then cooling the reaction mixture to form a crystal streamcomprising crystals of bisphenol and phenol and separating the crystalsfrom the crystal stream. The separated crystals are then melted to forma molten stream of bisphenol, phenol, and sulfur; and this molten streamis contacted with a base to reduce a sulfur concentration in the moltenstream and form a reduced sulfur stream. Phenol is then removed bydesorption from this reduced sulfur stream, leaving a product stream oflow sulfur-content bisphenol. In some exemplary embodiments, thepromoter comprises a catalyst selected from 3-mercaptopropionic acid,methyl mercaptan, ethyl mercaptan, 2,2-bis(methylthio)propane,mercaptocarboxylic acid, and combinations comprising at least one of theforegoing promoters. In some exemplary embodiments, the promotercomprises 3-mercaptopropionic acid. In some exemplary embodiments, thebase is an alkali solution. In some exemplary embodiments, the base isan anion exchange resin such as a tert-amine divinylbenzene/styrene ionexchange copolymer. In some exemplary embodiments, additional phenol isadded to the molten stream prior to contacting the stream with a base.

In some embodiments, a high-purity bisphenol useful in preparing thepolycarbonates used in the compositions described herein is preparedusing an attached promoter ion exchange resin catalyst system,optionally in conjunction with a solvent crystallization step. Thepreparation of such high-purity bisphenols is described in US2014/0051802A1 and US 2014/0051803A1, the disclosures of both of whichare incorporated herein by reference in their entirety. In someexemplary embodiments, a bisphenol is prepared by contacting a phenoland at least one of a ketone, an aldehyde, or a combination thereof inthe presence of an attached ion exchange resin catalyst comprising adimethyl thiazolidine promoter, without utilizing a pretreatment and/orpurification step for the phenol, ketone, and/or aldehyde. Solventcrystallization can be performed on reactor effluent from theabove-described reaction after flashing off phenol from the reactoreffluent.

“Polycarbonates” as used herein includes homopolycarbonates (whereineach R¹ in the polymer is the same), copolymers comprising different R¹moieties in the carbonate (“copolycarbonates”), copolymers comprisingcarbonate units and other types of polymer units, such as ester units,and combinations comprising at least one of homopolycarbonates and/orcopolycarbonates.

A specific type of copolymer is a polyester carbonate, also known as apolyester-polycarbonate. Such copolymers further contain, in addition torecurring carbonate chain units of formula (1), repeating units offormula (7)

wherein J is a divalent group derived from a dihydroxy compound, and canbe, for example, a C₂₋₁₀ alkylene, a C₆₋₂₀ cycloalkylene a C₆₋₂₀arylene, or a polyoxyalkylene group in which the alkylene groups contain2 to 6 carbon atoms, specifically 2, 3, or 4 carbon atoms; and T is adivalent group derived from a dicarboxylic acid, and can be, forexample, a C₂₋₁₀ alkylene, a C₆₋₂₀ cycloalkylene, or a C₆₋₂₀ arylene.Copolyesters containing a combination of different T and/or J groups canbe used. The polyesters can be branched or linear. In anotherembodiment, J is a C₂₋₃₀ alkylene group having a straight chain,branched chain, or cyclic (including polycyclic) structure. J can bederived from an aromatic dihydroxy compound of formula (3) above, orfrom an aromatic dihydroxy compound of formula (4) above, or from anaromatic dihydroxy compound of formula (6) above.

Aromatic dicarboxylic acids that can be used to prepare the polyesterunits include isophthalic or terephthalic acid,1,2-di(p-carboxyphenyl)ethane, 4,4′-dicarboxydiphenyl ether,4,4′-bisbenzoic acid, or a combination comprising at least one of theforegoing acids. Acids containing fused rings can also be present, suchas in 1,4-, 1,5-, or 2,6-naphthalenedicarboxylic acids. Specificdicarboxylic acids include terephthalic acid, isophthalic acid,naphthalene dicarboxylic acid, cyclohexane dicarboxylic acid, or acombination comprising at least one of the foregoing acids. A specificdicarboxylic acid comprises a combination of isophthalic acid andterephthalic acid wherein the weight ratio of isophthalic acid toterephthalic acid is 91:9 to 2:98. In another specific embodiment, J isa C₂₋₆ alkylene group and T is p-phenylene, m-phenylene, naphthalene, adivalent cycloaliphatic group, or a combination thereof. This class ofpolyester includes the poly(alkylene terephthalates).

The molar ratio of ester units to carbonate units in the copolymers canvary broadly, for example 1:99 to 99:1, specifically 10:90 to 90:10,more specifically 25:75 to 75:25, depending on the desired properties ofthe final composition.

In an embodiment, the polyester unit of a polyester-polycarbonate isderived from the reaction of a combination of isophthalic andterephthalic diacids (or derivatives thereof) with resorcinol. Inanother embodiment, the polyester unit of a polyester-polycarbonate isderived from the reaction of a combination of isophthalic acid andterephthalic acid with bisphenol A. In another embodiment, thepolycarbonate units are derived from bisphenol A. In another embodiment,the polycarbonate units are derived from resorcinol and bisphenol A in amolar ratio of resorcinol carbonate units to bisphenol A carbonate unitsof 1:99 to 99:1.

The polycarbonates described herein are manufactured by interfacialpolymerization. Although the reaction conditions for interfacialpolymerization can vary, a process generally involves dissolving ordispersing a dihydric phenol reactant in aqueous caustic soda or potash,adding the resulting mixture to a water-immiscible solvent medium, andcontacting the reactants with a carbonate precursor in the presence of acatalyst such as triethylamine and/or a phase transfer catalyst, undercontrolled pH conditions, e.g., 8 to 12. The most commonly used waterimmiscible solvents include methylene chloride, 1,2-dichloroethane,chlorobenzene, toluene, and the like.

Carbonate precursors include a carbonyl halide such as carbonyl bromideor carbonyl chloride, or a haloformate such as a bishaloformates of adihydric phenol (e.g., the bischloroformates of bisphenol A,hydroquinone, or the like) or a glycol (e.g., the bishaloformate ofethylene glycol, neopentyl glycol, polyethylene glycol, or the like).Combinations comprising at least one of the foregoing types of carbonateprecursors can also be used. Phosgene can also be a carbonate precursorin, an interfacial polymerization reaction to form carbonate linkages,which is referred to as a phosgenation reaction.

Among the phase transfer catalysts that can be used are catalysts of theformula (R³)₄Q⁺X, wherein each R³ is the same or different, and is aC₁₋₁₀ alkyl group; Q is a nitrogen or phosphorus atom; and X is ahalogen atom or a C₁₋₈ alkoxy group or C₆₋₁₈ aryloxy group. phasetransfer catalysts include, for example, [CH₃(CH₂)₃]₄NX, [CH₃(CH₂)₃]₄PX,[CH₃(CH₂)₅]₄NX, [CH₃(CH₂)₆]₄NX, [CH₃(CH₂)₄]₄NX, CH₃[CH₃(CH₂)₃]₃NX, andCH₃[CH₃(CH₂)₂]₃NX, wherein X is Cl⁻, Br⁻, a C₁₋₈ alkoxy group or a C₆₋₁₈aryloxy group. A phase transfer catalyst can be used in an amount of 0.1to 10 wt %, more specifically from 0.5 to 2 wt %, based on the weight ofbisphenol in the polymerization reaction mixture.

All types of polycarbonate end groups are contemplated as being usefulin the polycarbonate composition, provided that such end groups do notsignificantly adversely affect desired properties of the compositions.

Branched polycarbonate blocks can be prepared by adding a branchingagent during polymerization. These branching agents includepolyfunctional organic compounds containing at least three functionalgroups selected from hydroxyl, carboxyl, carboxylic anhydride,haloformyl, and mixtures of the foregoing functional groups. Specificexamples include trimellitic acid, trimellitic anhydride, trimellitictrichloride, tris-p-hydroxy phenyl ethane, isatin-bis-phenol,tris-phenol TC (1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene),tris-phenol PA (4(4(1,1-bis(p-hydroxyphenyl)-ethyl) alpha,alpha-dimethyl benzyl)phenol), 4-chloroformyl phthalic anhydride,trimesic acid, and benzophenone tetracarboxylic acid. The branchingagents can be added at a level of 0.05 to 2.0 wt %, based on the totalweight of the polymer. Mixtures comprising linear polycarbonates andbranched polycarbonates can be used.

A chain stopper (also referred to as a capping agent) can be includedduring polymerization. The chain stopper limits molecular weight growthrate, and so controls molecular weight in the polycarbonate. Chainstoppers include certain mono-phenolic compounds, mono-carboxylic acidchlorides, and/or mono-chloroformates. Mono-phenolic chain stoppers areexemplified by monocyclic phenols such as phenol and C₁-C₂₂alkyl-substituted phenols such as p-cumyl-phenol, resorcinolmonobenzoate, and p- and tertiary-butyl phenol; and monoethers ofdiphenols, such as p-methoxyphenol. Alkyl-substituted phenols withbranched chain alkyl substituents having 8 to 9 carbon atom can bespecifically mentioned. Certain mono-phenolic UV absorbers can also beused as a capping agent, for example4-substituted-2-hydroxybenzophenones and their derivatives, arylsalicylates, monoesters of diphenols such as resorcinol monobenzoate,2-(2-hydroxyaryl)-benzotriazoles and their derivatives,2-(2-hydroxyaryl)-1,3,5-triazines and their derivatives, and the like.

Mono-carboxylic acid chlorides can also be used as chain stoppers. Theseinclude monocyclic, mono-carboxylic acid chlorides such as benzoylchloride, C₁-C₂₂ alkyl-substituted benzoyl chloride, toluoyl chloride,halogen-substituted benzoyl chloride, bromobenzoyl chloride, cinnamoylchloride, 4-nadimidobenzoyl chloride, and combinations thereof;polycyclic, mono-carboxylic acid chlorides such as trimellitic anhydridechloride, and naphthoyl chloride; and combinations of monocyclic andpolycyclic mono-carboxylic acid chlorides. Chlorides of aliphaticmonocarboxylic acids with less than or equal to 22 carbon atoms areuseful. Functionalized chlorides of aliphatic monocarboxylic acids, suchas acryloyl chloride and methacryoyl chloride, are also useful. Alsouseful are mono-chloroformates including monocyclic,mono-chloroformates, such as phenyl chloroformate, alkyl-substitutedphenyl chloroformate, p-cumyl phenyl chloroformate, toluenechloroformate, and combinations thereof.

Polyester-polycarbonates can be prepared by techniques and materials asdescribed above for polycarbonates in general. Rather than utilizing thedicarboxylic acid or diol per se, the reactive derivatives of the acidor diol, such as the corresponding acid halides, in particular the aciddichlorides and the acid dibromides can be used. Thus, for exampleinstead of using isophthalic acid, terephthalic acid, or a combinationcomprising at least one of the foregoing acids, isophthaloyl dichloride,terephthaloyl dichloride, or a combination comprising at least one ofthe foregoing dichlorides can be used.

As mentioned above, the thermoplastic composition also includes an epoxyadditive having at least two epoxy groups per molecule. In someembodiments, the epoxy additive is an aliphatic epoxide having at leasttwo epoxy groups per molecule and a molecular weight lower than 600g/mol. Epoxy compounds useful as additives include epoxy modifiedacrylic oligomers or polymers (such as a styrene-acrylate-epoxy polymer,prepared from for example a combination of: a substituted orunsubstituted styrene such as styrene or 4-methylstyrene; an acrylate ormethacrylate ester of a C₁₋₂₂ alkyl alcohol such as methyl acrylate,methyl methacrylate, ethyl acrylate, butyl acrylate, or the like; and anepoxy-functionalized acrylate such as glycidyl acrylate, glycidylmethacrylate, 2-(3,4-epoxycyclohexyl)ethyl acrylate,2-(3,4-epoxycyclohexyl)ethyl methacrylate, or the like), or an epoxycarboxylate oligomer based on cycloaliphatic epoxides (such as, forexample, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, orthe like).

The epoxy additive may comprise an additional functional group such ashydroxyl, carboxylic acid, carboxylic acid ester, and the like. Morethan one functional group may be present. Specific examples of the epoxystabilizer include epoxidized soybean oil, epoxidized linseed oil,phenyl glycidyl ether, allyl glycidyl ether, tert-butylphenyl glycidylether, 3,4-epoxycyclohexylmethyl-3,4′-epoxy cyclohexyl carboxylate,3,4-epoxy-6-methylcylohexylmethyl-3′,4′-epoxy-6′-methylcyclohexylcarboxylate, 2,3 epoxycyclohexylmethyl-3′,4′-epoxycyclohexylcarboxylate, 4-(3,4-epoxy-5-methylcyclohexyl)butyl-3′,4′-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethyleneoxide,cyclohexylmethyl-3,4-epoxycyclohexyl carboxylate, 3,4epoxy-6-methylcyclohexylmethyl-6′-methylcyclohexyl carboxylate,bisphenol A glycidyl ether, tetrabromobisphenol A glycidyl ether,diglycidyl phthalate, diglycidyl hexahydro phthalate,bis-epoxydicyclopentadienyl ether, bis-epoxyethylene glycol,bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethyleneepoxide, octyl epoxyphthalate, epoxidized polybutadiene,3,4-dimethyl-1,2-epoxycyclo hexane, 3,5-dimethyl-1,2-epoxycyclohexane,3-methyl-5 tert-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl3,4-epoxycyclohexyl carboxylate,N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate,cyclohexyl-2-methyl-3,4 epoxycyclohexyl carboxylate,N-butyl-2-isopropyl-3,4 epoxy-5-methylcyclohexyl carboxylate,octadecyl-3,4 epoxycyclohexyl carboxylate, 2-ethylhexyl-3′,4′epoxycyclohexyl carboxylate, 4,6-dimethyl-2,3epoxycyclohexyl-3′,4′-epoxycyclohexyl carboxylate, 4,5epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5epoxytetrahydrophthalic anhydride, diethyl-4,5-epoxy-cis 1,2-cyclohexyldicarboxylate, and di-n-butyl-3-tert-butyl-4,5-epoxy-cis-1,2-cyclohexyldicarboxylate. The epoxy compounds can be used singly or in combination.Of these, epoxy carboxylates such as alicyclic epoxy carboxylates (e.g.,3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclo hexyl carboxylate) can beused.

In some embodiments, the epoxy additive is a carboxylate epoxy resincomprising a carboxylate diepoxide according to the formula:

Specific commercially available exemplary epoxy functionalizedstabilizers include Cycloaliphatic Epoxide Resin ERL-4221 supplied byUnion Carbide Corporation (a subsidiary of Dow Chemical), Danbury,Conn.; and epoxy functional acrylic (co)polymers such as JONCRYL™ADR-4300 and JONCRYL™ ADR-4368, available from BASF Corporation,Sturtevant, Wis. Epoxy additives can be used in different amounts, forexample from 0.01 to 0.25 wt. %, more specifically from 0.02 wt. % to0.10 wt. %, based on the weight of the thermoplastic composition.

As mentioned above, the thermoplastic composition also includes aphenolic diphosphite derived from pentaerythritol. In some embodiments,the phenolic diphosphite is a compound according to the formula:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, and R₁₀ each independentlyrepresents hydrogen or a C₁₋₂₀ organic radical. In some embodiments, theposition on the phenolic phenyl group to which the oxygen is attached ishindered, for example at the ortho and para positions. With respect tothe above formula, for example, in some embodiments R₂, R₅, R₅, R₇, R₉,and R₁₀ are H and R₁, R₂, R₆, and R₈ each independently represents aC₁₋₂₀ organic radical, more specifically an alkaryl radical of 4 to 13carbon atoms such as cumyl (e.g., bis(2,4-dicumyl)pentaerythritoldiphosphite). Examples of phenolic diphosphites are disclosed in U.S.Pat. Nos. 5,364,895; 5,438,086; 6,613,823, the disclosures of which areincorporated herein by reference in their entirety. Phenolicdiphosphates are also available commercially, e.g. under the Doverphos™brand, e.g., Doverphos™ S-9228 and from ADK palmarole (e.g. ADK STABPEP-36). The phenolic diphosphite can be present in the thermoplasticcomposition at different levels, for example, 0.02 wt. % to 0.30 wt. %,more specifically from 0.05 wt. % to 0.15 wt. %, based on the weight ofthe thermoplastic composition

The thermoplastic composition can further include additional additivesas described below, with the proviso that the additive(s) are selectedso as to not significantly adversely affect the desired properties ofthe thermoplastic composition, in particular the above-described opticalproperties. Such additives can be mixed at a suitable time during themixing of the components for forming the composition. additives includereinforcing agents, antioxidants, heat stabilizers, light stabilizers(including ultraviolet (UV) light stabilizers), plasticizers,lubricants, mold release agents, antistatic agents, surface effectadditives, radiation stabilizers, flame retardants, and anti-dripagents. Combinations of additives can also be used.

Antioxidant additives include additional organophosphites in addition tothe phenolic diphosphite derived from pentaerythritol, such astris(nonyl phenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite,distearyl pentaerythritol diphosphite; alkylated monophenols orpolyphenols; alkylated reaction products of polyphenols with dienes,such astetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane;butylated reaction products of para-cresol or dicyclopentadiene;alkylated hydroquinones; hydroxylated thiodiphenyl ethers;alkylidene-bisphenols; benzyl compounds; esters ofbeta-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid with monohydricor polyhydric alcohols; esters ofbeta-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid withmonohydric or polyhydric alcohols; esters of thioalkyl or thioarylcompounds such as distearylthiopropionate, dilaurylthiopropionate,ditridecylthiodipropionate,octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;amides of beta-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid, orcombinations comprising at least one of the foregoing antioxidants.Antioxidants are used in amounts of 0.01 to 0.1 parts by weight, basedon 100 parts by weight of the total composition.

Heat stabilizer additives include organophosphites such as triphenylphosphite, tris-(2,6-dimethylphenyl)phosphite, tris-(mixed mono- anddi-nonylphenyl)phosphite; phosphonates such as dimethylbenzenephosphonate, phosphates such as trimethyl phosphate, or combinationscomprising at least one of the foregoing heat stabilizers. Heatstabilizers are used in amounts of 0.01 to 0.1 parts by weight, based on100 parts by weight of the total composition.

Light stabilizers (including ultraviolet light (UV) absorbers) can alsobe used. Light stabilizers include benzotriazoles such as2-(2-hydroxy-5-methylphenyl)benzotriazole and2-(2-hydroxy-5-tert-octylphenyl)-benzotriazole, 2-hydroxy-4-n-octoxybenzophenone, or combinations comprising at least one of the foregoinglight stabilizers. Light stabilizers are used in amounts of 0.01 to 5parts by weight, based on 100 parts by weight of the total composition.

UV absorbers include hydroxybenzophenones; hydroxybenzotriazoles;hydroxybenzotriazines; cyanoacrylates; oxanilides; benzoxazinones;2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-phenol (CYASORB™5411); 2-hydroxy-4-n-octyloxybenzophenone (CYASORB™ 531);2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)-phenol(CYASORB™ 1164); 2,2′-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one)(CYASORB™ UV-3638);1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane(UVINUL* 3030); 2,2′-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one);1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane;phenol,2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)-(TINUVIN™ 234);BCAP bismalonate from Clariant; nano-size inorganic materials such astitanium oxide, cerium oxide, and zinc oxide, all with particle sizeless than or equal to 100 nanometers; or combinations comprising atleast one of the foregoing UV absorbers. UV absorbers are used inamounts of 0.01 to 5 parts by weight, based on 100 parts by weight ofthe total composition. Additives stabilizing against discoloration bygamma irradiation can also be used in the composition. Examples of suchstabilizers are polyether polyols, polyether polyolesters, aromaticdisulfides, hexylene glycol, poly(alkyleneglycol). Gamma stabilizingadditives can be present in levels of 0.01 to 1.0 parts by weight, basedon 100 parts by weight of the total composition.

Plasticizers, lubricants, and/or mold release agents can also be used.There is considerable overlap among these types of materials, whichinclude phthalic acid esters such asdioctyl-4,5-epoxy-hexahydrophthalate;tris-(octoxycarbonylethyl)isocyanurate; tristearin; di- orpolyfunctional aromatic phosphates such as resorcinol tetraphenyldiphosphate (RDP), the bis(diphenyl)phosphate of hydroquinone and thebis(diphenyl)phosphate of bisphenol A; poly-alpha-olefins; epoxidizedsoybean oil; silicones, including silicone oils; esters, for example,fatty acid esters such as alkyl stearyl esters, e.g., methyl stearate,stearyl stearate, pentaerythritol tetrastearate, and the like;combinations of methyl stearate and hydrophilic and hydrophobic nonionicsurfactants comprising polyethylene glycol polymers, polypropyleneglycol polymers, poly(ethylene glycol-co-propylene glycol) copolymers,or a combination comprising at least one of the foregoing glycolpolymers, e.g., methyl stearate and polyethylene-polypropylene glycolcopolymer in a solvent; waxes such as beeswax, montan wax, and paraffinwax. Such materials are used in amounts of 0.1 to 1 parts by weight,based on 100 parts by weight of the total composition.

Useful flame retardants include organic compounds that includephosphorus, bromine, and/or chlorine. Non-brominated and non-chlorinatedphosphorus-containing flame retardants can be preferred in certainapplications for regulatory reasons, for example organic phosphates andorganic compounds containing phosphorus-nitrogen bonds.

Flame retardant aromatic phosphates include triphenyl phosphate,tricresyl phosphate, isopropylated triphenyl phosphate, phenylbis(dodecyl)phosphate, phenyl bis(neopentyl)phosphate, phenylbis(3,5,5′-trimethylhexyl)phosphate, ethyl diphenyl phosphate,2-ethylhexyl di(p-tolyl)phosphate, bis(2-ethylhexyl) p-tolyl phosphate,tritolyl phosphate, bis(2-ethylhexyl) phenyl phosphate,tri(nonylphenyl)phosphate, bis(dodecyl) p-tolyl phosphate, dibutylphenyl phosphate, 2-chloroethyl diphenyl phosphate, p-tolylbis(2,5,5′-trimethylhexyl)phosphate, and 2-ethylhexyl diphenylphosphate. Di- or polyfunctional aromatic phosphorus-containingcompounds are also useful, for example resorcinol tetraphenyldiphosphate (RDP), the bis(diphenyl)phosphate of hydroquinone and thebis(diphenyl)phosphate of bisphenol A, respectively, and theiroligomeric and polymeric counterparts. flame retardant compoundscontaining phosphorus-nitrogen bonds include phosphonitrilic chloride,phosphorus ester amides, phosphoric acid amides, phosphonic acid amides,phosphinic acid amides, and tris(aziridinyl)phosphine oxide. When used,phosphorus-containing flame retardants are present in amounts of 0.1 to30 parts by weight, more specifically 1 to 20 parts by weight, based on100 parts by weight of the total composition.

Halogenated materials can also be used as flame retardants, for examplebisphenols of which the following are representative:2,2-bis-(3,5-dichlorophenyl)-propane; bis-(2-chlorophenyl)-methane;bis(2,6-dibromophenyl)-methane; 1,1-bis-(4-iodophenyl)-ethane;1,2-bis-(2,6-dichlorophenyl)-ethane;1,1-bis-(2-chloro-4-iodophenyl)ethane;1,1-bis-(2-chloro-4-methylphenyl)-ethane;1,1-bis-(3,5-dichlorophenyl)-ethane;2,2-bis-(3-phenyl-4-bromophenyl)-ethane;2,6-bis-(4,6-dichloronaphthyl)-propane; and2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane 2,2bis-(3-bromo-4-hydroxyphenyl)-propane. Other halogenated materialsinclude 1,3-dichlorobenzene, 1,4-dibromobenzene,1,3-dichloro-4-hydroxybenzene, and biphenyls such as2,2′-dichlorobiphenyl, polybrominated 1,4-diphenoxybenzene,2,4′-dibromobiphenyl, and 2,4′-dichlorobiphenyl as well as decabromodiphenyl oxide, as well as oligomeric and polymeric halogenated aromaticcompounds, such as a copolycarbonate of bisphenol A andtetrabromobisphenol A and a carbonate precursor, e.g., phosgene. Metalsynergists, e.g., antimony oxide, can also be used with the flameretardant. When present, halogen containing flame retardants are presentin amounts of 1 to 25 parts by weight, more specifically 2 to 20 partsby weight, based on 100 parts by weight of the total composition.Alternatively, the thermoplastic composition can be essentially free ofchlorine and bromine “Essentially free of chlorine and bromine” isdefined as having a bromine and/or chlorine content of less than orequal to 100 parts per million by weight (ppm), less than or equal to 75ppm, or less than or equal to 50 ppm, based on the total parts by weightof the composition.

Inorganic flame retardants can also be used, for example salts of C₁₋₁₆alkyl sulfonate salts such as potassium perfluorobutane sulfonate (Rimarsalt), potassium perfluoroctane sulfonate, tetraethylammoniumperfluorohexane sulfonate, and potassium diphenylsulfone sulfonate;salts such as Na₂CO₃, K₂CO₃, MgCO₃, CaCO₃, and BaCO₃, or fluoro-anioncomplexes such as Li₃AlF₆, BaSiF₆, KBF₄, K₃AlF₆, KAlF₄, K₂SiF₆, and/orNa₃AlF₆. When present, inorganic flame retardant salts are present inamounts of 0.01 to 10 parts by weight, more specifically 0.02 to 1 partsby weight, based on 100 parts by weight of the total composition.

Tinting colorants can be added to the thermoplastic composition toachieve specifically targeted color space values, subject to compliancewith L* specifications or other specifications described herein orelsewhere. Colorants include, for example, anthraquinones, perylenes,perinones, indanthrones, quinacridones, xanthenes, oxazines, oxazolines,thioxanthenes, indigoids, thioindigoids, naphtalimides, cyanines,xanthenes, methines, lactones, coumarins, bis-benzoxaxolylthiophenes(BBOT), napthalenetetracarboxylic derivatives, monoazo and disazopigments, triarylmethanes, aminoketones, bis(styryl)biphenylderivatives, and the like, as well as combinations comprising at leastone of the foregoing colorants. The amount of colorant depends on thetarget color properties for the article, the spectral absorbanceproperties of the colorant(s), and the intrinsic color properties of thepolycarbonate and any other materials or additives in the thermoplasticcomposition. The amount can vary, provided that it is kept below thelevel at which L* falls below target specifications, in some embodimentsan L* value of 95.65, in some embodiments an L* value of 95.75, and insome embodiments an L* value of 98.85. Exemplary amounts can range from0.00005 to 0.01 parts by weight per 100 parts by weight of polycarbonateresin.

Specific exemplary colorants include organic dyes such as coumarin 460(blue), coumarin 6 (green), nile red or the like; lanthanide complexes;hydrocarbon and substituted hydrocarbon dyes; polycyclic aromatichydrocarbons; scintillation dyes (preferably oxazoles and oxadiazoles);aryl- or heteroaryl-substituted poly(2-8 olefins); carbocyanine dyes;phthalocyanine dyes and pigments; oxazine dyes; carbostyryl dyes;porphyrin dyes; acridine dyes; anthraquinone dyes; arylmethane dyes; azodyes; diazonium dyes; nitro dyes; quinone imine dyes; tetrazolium dyes;thiazole dyes; perylene dyes, perinone dyes; bis-benzoxazolylthiophene(BBOT); and xanthene dyes; fluorophores such as anti-stokes shift dyeswhich absorb in the near infrared wavelength and emit in the visiblewavelength, or the like; luminescent dyes such as5-amino-9-diethyliminobenzo(a)phenoxazonium perchlorate;7-amino-4-methylcarbostyryl; 7-amino-4-methylcoumarin;7-amino-4-trifluoromethylcoumarin;3-(2′-benzimidazolyl)-7-N,N-diethylaminocoumarin;3-(2′-benzothiazolyl)-7-diethylaminocoumarin;2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole;2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole;2-(4-biphenyl)-6-phenylbenzoxazole-1,3;2,5-Bis-(4-biphenylyl)-1,3,4-oxadiazole; 2,5-bis-(4-biphenylyl)-oxazole;4,4′-bis-(2-butyloctyloxy)-p-quaterphenyl;p-bis(o-methylstyryl)-benzene; 5,9-diaminobenzo(a)phenoxazoniumperchlorate;4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran;1,1′-diethyl-2,2′-carbocyanine iodide; 1,1′-diethyl-4,4′-carbocyanineiodide; 3,3′-diethyl-4,4′,5,5′-dibenzothiatricarbocyanine iodide;1,1′-diethyl-4,4′-dicarbocyanine iodide;1,1′-diethyl-2,2′-dicarbocyanine iodide;3,3′-diethyl-9,11-neopentylenethiatricarbocyanine iodide;1,3′-diethyl-4,2′-quinolyloxacarbocyanine iodide;1,3′-diethyl-4,2′-quinolylthiacarbocyanine iodide;3-diethylamino-7-diethyliminophenoxazonium perchlorate;7-diethylamino-4-methylcoumarin;7-diethylamino-4-trifluoromethylcoumarin; 7-diethylaminocoumarin;3,3′-diethyloxadicarbocyanine iodide; 3,3′-diethylthiacarbocyanineiodide; 3,3′-diethylthiadicarbocyanine iodide;3,3′-diethylthiatricarbocyanine iodide;4,6-dimethyl-7-ethylaminocoumarin; 2,2′-dimethyl-p-quaterphenyl;2,2-dimethyl-p-terphenyl;7-dimethylamino-1-methyl-4-methoxy-8-azaquinolone-2;7-dimethylamino-4-methylquinolone-2;7-dimethylamino-4-trifluoromethylcoumarin;2-(4-(4-dimethylaminophenyl)-1,3-butadienyl)-3-ethylbenzothiazoliumperchlorate;2-(6-(p-dimethylaminophenyl)-2,4-neopentylene-1,3,5-hexatrienyl)-3-methylbenzothiazoliumperchlorate;2-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-1,3,3-trimethyl-3H-indoliumperchlorate; 3,3′-dimethyloxatricarbocyanine iodide; 2,5-diphenylfuran;2,5-diphenyloxazole; 4,4′-diphenylstilbene;1-ethyl-4-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-pyridiniumperchlorate;1-ethyl-2-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-pyridiniumperchlorate;1-Ethyl-4-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-quinoliumperchlorate; 3-ethylamino-7-ethylimino-2,8-dimethylphenoxazin-5-iumperchlorate; 9-ethylamino-5-ethylamino-10-methyl-5H-benzo(a)phenoxazonium perchlorate;7-ethylamino-6-methyl-4-trifluoromethylcoumarin;7-ethylamino-4-trifluoromethylcoumarin;1,1′,3,3,3′,3′-hexamethyl-4,4′,5,5′-dibenzo-2,2′-indotricarboccyanineiodide; 1,1′,3,3,3′,3′-hexamethylindodicarbocyanine iodide;1,1′,3,3,3′,3′-hexamethylindotricarbocyanine iodide;2-methyl-5-t-butyl-p-quaterphenyl;N-methyl-4-trifluoromethylpiperidino-<3,2-g>coumarin;3-(2′-N-methylbenzimidazolyl)-7-N,N-diethylaminocoumarin;2-(1-naphthyl)-5-phenyloxazole; 2,2′-p-phenylen-bis(5-phenyloxazole);3,5,3″″,5″″-tetra-t-butyl-p-sexiphenyl;3,5,3″″,5″″-tetra-t-butyl-p-quinquephenyl;2,3,5,6-1H,4H-tetrahydro-9-acetylquinolizino-<9,9a,1-gh>coumarin;2,3,5,6-1H,4H-tetrahydro-9-carboethoxyquinolizino-<9,9a,1-gh>coumarin;2,3,5,6-1H,4H-tetrahydro-8-methylquinolizino-<9,9a,1-gh>coumarin;2,3,5,6-1H,4H-tetrahydro-9-(3-pyridyl)-quinolizino-<9,9a,1-gh>coumarin;2,3,5,6-1H,4H-tetrahydro-8-trifluoromethylquinolizino-<9,9a,1-gh>coumarin;2,3,5,6-1H,4H-tetrahydroquinolizino-<9,9a,1-gh>coumarin;3,3′,2″,3′″-tetramethyl-p-quaterphenyl;2,5,2″″,5′″-tetramethyl-p-quinquephenyl; P-terphenyl; P-quaterphenyl;nile red; rhodamine 700; oxazine 750; rhodamine 800; IR 125; IR 144; IR140; IR 132; IR 26; IRS; diphenylhexatriene; diphenylbutadiene;tetraphenylbutadiene; naphthalene; anthracene; 9,10-diphenylanthracene;pyrene; chrysene; rubrene; coronene; phenanthrene or the like,3-hydroxyflavones such as disclosed in US 2009/0054586 A1, orcombinations comprising at least one of the foregoing dyes.

The thermoplastic compositions can be manufactured by various methods.For example, powdered polycarbonate, impact modifier, epoxy additive,phenolic diphosphite, and/or other optional components can be firstblended in a HENSCHEL-Mixer™ high speed mixer. Other low shearprocesses, including but not limited to hand mixing, can also accomplishthis blending. The blend is then fed into the throat of a twin-screwextruder via a hopper. Alternatively, at least one of the components canbe incorporated into the composition by feeding directly into theextruder at the throat and/or downstream through a sidestuffer.Additives can also be compounded into a masterbatch with a desiredpolymeric resin and fed into the extruder. The extruder is generallyoperated at a temperature higher than that necessary to cause thecomposition to flow. The extrudate is immediately quenched in a waterbatch and pelletized. The pellets, so prepared, when cutting theextrudate can be one-fourth inch long or less as desired. Such pelletscan be used for subsequent molding, shaping, or forming.

The thermoplastic compositions are further illustrated by the followingnon-limiting examples.

EXAMPLES

The following components are used in the examples. PC1 was preparedusing a bisphenol having sulfur content less than 2 ppm by weight andless than 150 ppm hydroxyl content, according to US2013/0035441A1 andUS2013/0108820 A1. Unless specifically indicated otherwise, the amountof each component is in weight percent in the following examples, basedon the total weight of the composition.

TABLE 1 Acronym Component Source PC1 BPA polycarbonate, MW about 30,000,SABIC CAS: 25971-63-5 PC2 BPA polycarbonate, MW about 30,000 SABIC CAS:25971-63-5 I-168 Irgaphos ™ 168, CIBA tris(2,4-di-t-butylphenyl)phosphite CAS: 31570-04-4 D S-9228 Doverphos ™ S-9228, Doverbis(2,4-dicumyl) pentaerythritol Chemical diphosphite CAS: 154862-43-8PEP 36 ADK stab PEP 36, Bis(tri-alkylated ADEKA phenyl)-PEDP CAS:80693-00-1 PALMAROLE TPP Triphenylphosphine BASF CAS: 603-35-0 A 1076Antioxidant 1076, CHEMTURA Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, CAS: 2082-79-3 CA Epoxy Cycloaliphatic EpoxyResin, IMCDgroup 3,4-epoxycyclohexylmethyl-3,4- epoxycyclohexylcarboxylate CAS: 2386-87-0 Epoxydized Epoxidized Soyabean Oil SigmaAldrich SB oil CAS: 8013-07-8 DER 671 DER 671 Epoxy Resin, Hexion EpoxyBisphenol A-(epichlorohydrin); Specialty epoxy resin (avg: Mw 700-1100)Chemicals CAS: 25068-38-6

All thermoplastic compositions except where indicated are compounded onan intermeshing co-rotating twin-screw extruder to form pellets of thecomposition, using a temperature of 280° C. to 300° C. and a heatingresidence time of about 30 seconds. The compositions are subsequentlymolded using an ENGEL 75T injection molder with AXXICON insert moldsystem to mold 60 mm×60 mm×2.5 mm color test plaques at standard moldingconditions with a temperature of about 290° C. and a residence timeabout 5 minutes.

The plaques are first measured for color on a Macbeth 7000Aspectrophotometer in transmission mode and UV excluded. CIELAB 1976color values (L*, a*, b*) (ISO 11664-4:2008(E)/CIE S 014-4/E:2007 aredetermined from the absorption spectrum of a 2.5 mm thick color plaquebetween 400 nm and 700 nm. Yellowness index (YI) values can becalculated according to ASTM D1925-E313. The plaques can also bemeasured for transmission and haze according to ASTM D1003-00 using aBYK Gardner Haze-gard dual. After initial color measurements, theplaques are subjected to aging in a circulating air oven at 130° C. forup to 2000 hours. Periodically (after aging for 50 hours, 250 hours, 500hours, 750 hours, 1000 hours, and 2000 hours), the samples are removedfrom the oven, measured for color as described above, and returned tothe oven. The change in color after aging, expressed as dE (2000 hrs.).

Examples 1-4 and Comparative Examples 1-10

Plaques were prepared from thermoplastic compositions as set forth inTables 2, 3 and 4 and subjected to aging with color measurements asdescribed above. CIELAB 1976 L*, a*, and b* values, along with dE (2000hrs.) values based on a comparison of initial color measurements andcolor measurements taken after 2000 hours of aging at 130° C., are shownin Tables 2, 3 and 4 according to ISO 11664-4:2008(E)/CIE S 014-4/E:2007using CIE illuminant D65 and a 2.5 mm thick molded plaque of thethermoplastic composition.

TABLE 2 PC1 PC2 1-168 D S-9228 sample (% wt) (% wt) (% wt) (% wt) PEP 36(% wt) TPP (% wt) A 1076 (% wt) L* a* b* dE (2000 hrs.) CE1 100 95.83−0.08 0.80 1.70 CE2 100 95.54 −0.18 1.47 5.86 CE3 99.95 0.05 95.83 −0.080.63 2.38 CE4 99.9 0.1 95.90 −0.05 0.58 2.24 CE5 99.8 0.2 95.90 −0.040.54 6.21 CE6 99.95 0.05 95.84 −0.06 0.56 5.49 CE7 99.9 0.1 95.87 −0.050.51 7.49 CE8 99.8 0.2 95.90 −0.03 0.49 52.54 CE9 99.95 0.05 95.88 −0.050.52 4.03 CE10 99.9 0.1 95.90 −0.03 0.52 30.28 CE11 99.8 0.2 95.94 −0.030.45 70.75 CE12 99.95 0.05 95.87 −0.06 0.53 3.34 CE13 99.9 0.1 95.92−0.04 0.48 2.90 CE14 99.8 0.2 95.91 −0.06 0.54 4.01 CE15 99.9 0.1 95.76−0.09 0.83 11.50 CE16 99.98 0.02 95.87 −0.07 0.63 1.09 CE17 99.96 0.0495.85 −0.08 0.75 1.71 CE18 99.93 0.05 0.02 95.85 −0.06 0.57 0.99 CE4299.97 0.01 0.02 95.85 −0.07 0.57 1.17 CE19 99.93 0.05 0.02 95.87 −0.060.54 1.41 CE20 99.88 0.1 0.02 95.90 −0.05 0.49 2.46 CE21 99.78 0.2 0.0295.90 −0.06 0.49 24.93 CE22 99.93 0.05 0.02 95.92 −0.05 0.50 9.85 CE2399.88 0.1 0.02 95.92 −0.05 0.49 36.54 CE24 99.93 0.05 0.02 95.91 −0.040.48 4.48 CE25 99.88 0.1 0.02 95.90 −0.04 0.48 5.75

TABLE 3 PC1 PC2 I-168 D S-9228 PEP 36 TPP A 1076 CA Epoxy dE sample (%wt) (% wt) (% wt) (% wt) (% wt) (% wt) (% wt) (% wt) L* a* b* (2000hrs.) CE26 99.9 0.1 95.81 −0.08 0.80 2.59 CE27 99.95 0.05 95.84 −0.090.75 1.74 CE30 99.85 0.1 0.05 95.91 −0.05 0.56 1.67 CE31 99.7 0.2 0.195.90 −0.04 0.53 1.36 EX1 99.85 0.1 0.05 95.90 −0.04 0.50 1.93 EX2 99.70.2 0.1 95.90 −0.03 0.47 1.76 EX3 99.85 0.1 0.05 95.92 −0.04 0.52 1.88CE32 99.7 0.2 0.1 95.93 −0.03 0.46 14.71 CE33 99.85 0.1 0.05 95.91 −0.100.63 2.54 CE34 99.7 0.2 0.1 95.88 −0.10 0.69 4.15 CE37 99.85 0.1 0.0595.70 −0.11 0.95 9.78 CE38 99.93 0.02 0.05 95.85 −0.08 0.76 1.00 CE3999.83 0.1 0.02 0.05 95.91 −0.05 0.57 0.78 EX7 99.92 0.01 0.02 0.05 95.88−0.06 0.57 0.71 EX6 99.88 0.05 0.02 0.05 95.88 −0.04 0.52 0.79 EX4 99.830.1 0.02 0.05 95.90 −0.05 0.50 0.84 EX5 99.83 0.1 0.02 0.05 95.92 −0.040.49 1.81 CE40 99.83 0.1 0.02 0.05 95.90 −0.11 0.66 1.90

TABLE 4 sample PC1 (% wt) D S-9228 (% wt) Epoxydized SB oil (% wt) DER671 Epoxy (% wt) L* a* b* dE (2000 hrs.) CE28 99.95 0.05 95.85 −0.090.76 1.66 CE29 99.95 0.05 95.83 −0.09 0.80 1.60 CE35 99.85 0.1 0.0595.87 −0.05 0.61 2.33 CE36 99.85 0.1 0.05 95.89 −0.05 0.55 2.22

As shown in Table 2, phosphite stabilizers as well as triphenylphospine(CE3 to CE14) give better starting color (lower b*) after processingcompared to polycarbonate without stabilizers (CE1). Pentaerithrol basedphosphites are more effective in reducing color than the otherstabilizers. All these P-containing stabilizers lead to worse colorstability (higher delta E). This effect is again the strongest forpentaerithrol based phosphites. Table 2 also shows that PC1 leads tolower color and improved color stability than PC2. Table 2 also showsthat for many polycarbonate compositions, such as those having a freehydroxy content of greater than 150 ppm and/or prepared from a bisphenolhaving a sulfur content of greater than 2 ppm by weight, the epoxyadditive can actually increase the yellowness of molded articles. See,e.g., a comparison of CE15 and CE37 in Tables 2 and 3.

The addition of Antioxidant 1076 has a positive effect on colorstability, as shown by examples CE16 to CE25, but in combination withhigher levels of pentaerithrol based stabilizers, discoloration remainshigher than the target value of 2.0. In combination with anotherphosphite stabilizer such as 1-168, color stability is good, but initialcolor is too yellow (CE16, CE17) b*>0.56.

The use of epoxide typically does not lead to improved color stabilityas shown by the samples in Tables 2 and 3. Comparing CE26 and CE27 withCE1, it is shown that higher levels of epoxy reduce color stability.Surprisingly however, it was found that the epoxide can improve colorstability when it is used in combination with phosphites, in particularthose based on pentaerithrol such as Doverphos S-9228 and ADK STBPEP-36. This is illustrated by comparing EX1 and EX2 with CE7 and CE8,comparing EX3 and CE32 with CE10 and CE11 and by comparing EX4 and EX5with CE20 and CE23. The comparison is shown graphically in FIGS. 3 and4, which plot dE as a function of the D S-9882 phosphite forcompositions with and without epoxide. The plots show a sharp increasein dE (2000 hrs.) when Doverphos level exceeds 0.1 wt. % for thecomposition without an epoxide, but stable dE (2000 hrs.) at Doverphoslevels over 0.1 wt. % for the composition with the epoxide additive.

Table 4 shows that not all epoxy containing materials are effective.Epoxydized soybean oil and DER 671 epoxy do not result in colorstability improvement.

Set forth below are some embodiments of the illuminating device andmethods of making and using the same.

-   -   Embodiment 1: An illuminating device, comprising: a light        source; and a light-transmitting article formed from a        thermoplastic composition, positioned to provide a light        transmission path from the light source through the        light-transmitting article, with a distance, d, between the        light source and the light-transmitting article of less than 40        mm, the light transmission path extending through the        light-transmitting article and optionally through other        light-transmitting article(s) comprising the thermoplastic        composition such that the total distance, p, of the light        transmission path through the light-transmitting article is at        least 3 mm; wherein the thermoplastic composition comprises a        polycarbonate having repeating structural carbonate units        according to the formula

in which at least 60 percent of the total number of R¹ groups containaromatic moieties and the balance thereof are aliphatic, alicyclic, oraromatic; the polycarbonate having been prepared through an interfacialpolymerization process from BPA monomer having an organic purity higherthan 99.70% by weight and having a hydroxyl content lower than 150 ppmby weight; 0.01 wt. % to 0.30 wt. %, based on the total weight of thethermoplastic composition, of an epoxy additive having at least twoepoxy groups per molecule; and 0.01 wt. % to 0.30 wt. %, based on thetotal weight of the thermoplastic composition, of a phenolic diphosphitederived from pentaerythritol; wherein the thermoplastic composition hasa sulfur content lower than 2 ppm, and wherein the thermoplasticcomposition exhibits a dE (2000 hrs.) value of less than 2.0 after 2000hours of heat aging at 130° C., measured according ISO11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mmthick molded plaque of the thermoplastic composition.

-   -   Embodiment 2: The illuminating device of Embodiment 1, wherein p        is at least 5 mm.    -   Embodiment 3: The illuminating device of Embodiment 1, wherein p        is at least 10 mm.    -   Embodiment 4: The illuminating device of Embodiment 1, wherein p        is at least 20 mm.    -   Embodiment 5: The illuminating device of any of Embodiments 1-4,        wherein d is less than 20 mm.    -   Embodiment 6: The illuminating device of any of Embodiments 1-4,        wherein d is less than 10 mm.    -   Embodiment 7: The illuminating device of any of Embodiments 1-4,        wherein d is less than 5 mm.    -   Embodiment 8: The illuminating device of any of Embodiments 1-4,        wherein d is 0.    -   Embodiment 9: The illuminating device of any of Embodiments 1-8,        wherein the thermoplastic composition exhibits the dE value of        less than 1.50 after 2000 hours of heat aging at 130° C.,        measured according ISO 11664-4:2008(E)/CIE S 014-4/E:2007 using        CIE illuminant D65 and a 2.5 mm thick molded plaque of the        thermoplastic composition.    -   Embodiment 10: The illuminating device of any of Embodiments        1-8, wherein the thermoplastic composition exhibits the dE value        of less than 0.95 after 2000 hours of heat aging at 130° C.,        measured according ISO 11664-4:2008(E)/CIE S 014-4/E:2007 using        CIE illuminant D65 and a 2.5 mm thick molded plaque of the        thermoplastic composition.    -   Embodiment 11: The illuminating device of any of Embodiments        1-10, wherein the thermoplastic composition exhibits a b*<0.56        and a L*>95.65 as measured according ISO 11664-4:2008(E)/CIE S        014-4/E:2007 using CIE illuminant D65 and a 2.5 mm thick molded        plaque of the thermoplastic composition.    -   Embodiment 12: The illuminating device of any of Embodiments        1-10, wherein the thermoplastic composition exhibits a b* of        <0.54 and a L*>95.75 as measured according ISO        11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and        a 2.5 mm thick molded plaque of the thermoplastic composition.    -   Embodiment 13: The illuminating device of any of Embodiments        1-10, wherein the thermoplastic composition exhibits a b* of        <0.52 and a L*>98.85 as measured according ISO        11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and        a 2.5 mm thick molded plaque of the thermoplastic composition.    -   Embodiment 14: The illuminating device of any of Embodiments        1-13, wherein the epoxy additive is an aliphatic epoxide having        at least two epoxy groups per molecule and a molecular weight        less than 600 g/mol.    -   Embodiment 15: The illuminating device of any of Embodiments        1-13, wherein the epoxy additive is a carboxylate epoxy resin.    -   Embodiment 16: The illuminating device of Embodiment 15, wherein        the epoxy additive is a carboxylate epoxy resin comprising a        carboxylate diepoxide according to the formula:

-   -   Embodiment 17: The illuminating device of any of Embodiments        1-16, wherein the phenolic diphosphite is according to the        formula:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, and R₁₀ each independentlyrepresents hydrogen or a C₁₋₂₀ organic radical.

-   -   Embodiment 18: The illuminating device of Embodiment 17, wherein        R₂, R₅, R₅, R₇, R₉, and R₁₀ are H and R₁, R₂, R₆, and R₈ each        independently represents a C₁₋₂₀ organic radical.    -   Embodiment 19: The illuminating device of Embodiment 18, wherein        R₁, R₃, R₆, and R₈ each independently represents an alkaryl        radical of 4 to 13 carbon atoms.    -   Embodiment 20: The illuminating device of Embodiment 19, wherein        R₁, R₃, R₆, and R₈ are each cumyl.    -   Embodiment 21: The illuminating device of Embodiment 17 wherein        at least 40% of the R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, and R₁₀        groups are cumyl.    -   Embodiment 22: The illuminating device of any of Embodiments        1-16, wherein at least 90% of the R¹ groups are derived from the        bisphenol.    -   Embodiment 23: The illuminating device of Embodiment 22, wherein        all of the R¹ groups are derived from the bisphenol.    -   Embodiment 24: The illuminating device of any of Embodiments        1-23, wherein the bisphenol is bisphenol A.    -   Embodiment 25: The illuminating device of Embodiments 1-24,        wherein the thermoplastic composition comprises from 0.02 wt. %        to 0.10 wt. % of the epoxy additive.    -   Embodiment 26: The illuminating device of Embodiments 1-25        wherein the thermoplastic composition comprises from 0.05 wt. %        to 0.20 wt. % of the phenolic diphosphite.    -   Embodiment 27: The illuminating device of any of Embodiments        1-26, wherein the light-transmitting article is an illuminant        lens, illuminant cover, a light guide, or an optical sheet.    -   Embodiment 28: The illuminating device of any of Embodiments 27,        wherein the light-transmitting article comprises a light guide        wherein p is at least 7 mm.    -   Embodiment 29: The illuminating device of any of Embodiments        1-28, wherein the illuminating device is a display object, a        toy, furniture, an art object, or a light.    -   Embodiment 30: The illuminating device of Embodiment 29, wherein        the illuminating device is a motor vehicle headlamp.    -   Embodiment 31: The illuminating device of any of Embodiments        1-30, wherein the light-transmitting article comprises an        aspheric lens.    -   Embodiment 32: The illuminating device of any of Embodiments        1-31, wherein the light-transmitting article is a first lens        along said light transmission path, and further comprising a        second lens along said light transmission path further from the        light source than the first lens, said second lens comprises the        thermoplastic composition.    -   Embodiment 33: The illuminating device of any of Embodiments        1-32, wherein the light source is a light-emitting diode.    -   Embodiment 34: The illuminating device of any of Embodiments        1-32, wherein the light source is a xenon arc lamp.    -   Embodiment 35: The illuminating device of any of Embodiments        1-34, wherein the light-transmitting article reaches a        temperature between 80° C. and 135° C. during operation.    -   Embodiment 36: The illuminating device of any of Embodiments        1-34, wherein the sulfur content is greater than 0 to less than        2 ppm.    -   Embodiment 37: The illuminating device of Embodiment 36, wherein        the sulfur content is 0.5 ppm to less than 2 ppm.    -   Embodiment 38: The illuminating device of Embodiment 36, wherein        the sulfur content is less than 0.5 ppm.    -   Embodiment 39: A method of using the device of any of        Embodiments 1-38, comprising illuminating the light-transmitting        article with the light source under conditions to subject the        light-transmitting article to a temperature of 80° C. to 135° C.    -   Embodiment 40: The method of Embodiment 39, wherein the        light-transmitting article is subjected to a temperature 80° C.        to 135° C. for a cumulative duration of at least 500 hours.    -   Embodiment 41: A method for making the illuminating device of        any of Embodiments 1-38, comprising: disposing the light source        the distance d of less than 40 mm from the light-transmitting        plastic article such that the total distance, p, of the light        transmission path is at least 3 mm.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise. “Or” means “and/or.” Themodifier “about” used in connection with a quantity is inclusive of thestated value and has the meaning dictated by the context (e.g., includesthe degree of error associated with measurement of the particularquantity). The notation “±10%” means that the indicated measurement canbe from an amount that is minus 10% to an amount that is plus 10% of thestated value. The terms “front”, “back”, “bottom”, and/or “top” are usedherein, unless otherwise noted, merely for convenience of description,and are not limited to any one position or spatial orientation. Theendpoints of all ranges directed to the same component or property areinclusive and independently combinable (e.g., ranges of “less than orequal to 25 wt %, or 5 wt % to 20 wt %,” is inclusive of the endpointsand all intermediate values of the ranges of “5 wt % to 25 wt %,” etc.).The suffix “(s)” is intended to include both the singular and the pluralof the term that it modifies, thereby including at least one of thatterm (e.g., ‘the colorant(s)’ includes a single colorant or two or morecolorants, i.e., at least one colorant). “Optional” or “optionally”means that the subsequently described event or circumstance can orcannot occur, and that the description includes instances where theevent occurs and instances where it does not. A “combination” isinclusive of blends, mixtures, alloys, reaction products, and the like.Unless otherwise specified, all optical parameters herein are measuredon 2.5 mm thick plaques. Unless otherwise specified, parts per million(ppm) is by weight.

As used herein, the term “hydrocarbyl” and “hydrocarbon” refers broadlyto a substituent comprising carbon and hydrogen, optionally with 1 to 3heteroatoms, for example, oxygen, nitrogen, halogen, silicon, sulfur, ora combination thereof; “alkyl” refers to a straight or branched chain,saturated monovalent hydrocarbon group; “alkylene” refers to a straightor branched chain, saturated, divalent hydrocarbon group; “alkylidene”refers to a straight or branched chain, saturated divalent hydrocarbongroup, with both valences on a single common carbon atom; “alkenyl”refers to a straight or branched chain monovalent hydrocarbon grouphaving at least two carbons joined by a carbon-carbon double bond;“cycloalkyl” refers to a non-aromatic monovalent monocyclic ormulticyclic hydrocarbon group having at least three carbon atoms,“cycloalkenyl” refers to a non-aromatic cyclic divalent hydrocarbongroup having at least three carbon atoms, with at least one degree ofunsaturation; “aryl” refers to an aromatic monovalent group containingonly carbon in the aromatic ring or rings; “arylene” refers to anaromatic divalent group containing only carbon in the aromatic ring orrings; “alkylaryl” refers to an aryl group that has been substitutedwith an alkyl group as defined above, with 4-methylphenyl being anexemplary alkylaryl group; “arylalkyl” refers to an alkyl group that hasbeen substituted with an aryl group as defined above, with benzyl beingan exemplary arylalkyl group; “acyl” refers to an alkyl group as definedabove with the indicated number of carbon atoms attached through acarbonyl carbon bridge (—C(═O)—); “alkoxy” refers to an alkyl group asdefined above with the indicated number of carbon atoms attached throughan oxygen bridge (—O—); and “aryloxy” refers to an aryl group as definedabove with the indicated number of carbon atoms attached through anoxygen bridge (—O—).

Unless otherwise indicated, each of the foregoing groups can beunsubstituted or substituted, provided that the substitution does notsignificantly adversely affect synthesis, stability, or use of thecompound. The term “substituted” as used herein means that at least onehydrogen on the designated atom or group is replaced with another group,provided that the designated atom's normal valence is not exceeded. Whenthe substituent is oxo (i.e., ═O), then two hydrogens on the atom arereplaced. Combinations of substituents and/or variables are permissibleprovided that the substitutions do not significantly adversely affectsynthesis or use of the compound. Exemplary groups that can be presenton a “substituted” position include, but are not limited to, cyano;hydroxyl; nitro; azido; alkanoyl (such as a C2-6 alkanoyl group such asacyl); carboxamido; C1-6 or C1-3 alkyl, cycloalkyl, alkenyl, and alkynyl(including groups having at least one unsaturated linkages and from 2 to8, or 2 to 6 carbon atoms); C1-6 or C1-3 alkoxy groups; C6-10 aryloxysuch as phenoxy; C1-6 alkylthio; C1-6 or C1-3 alkylsulfinyl; C1-6 orC1-3 alkylsulfonyl; aminodi(C1-6 or C1-3)alkyl; C6-12 aryl having atleast one aromatic rings (e.g., phenyl, biphenyl, naphthyl, or the like,each ring either substituted or unsubstituted aromatic); C7-19alkylenearyl having 1 to 3 separate or fused rings and from 6 to 18 ringcarbon atoms, with benzyl being an exemplary arylalkyl group; orarylalkoxy having 1 to 3 separate or fused rings and from 6 to 18 ringcarbon atoms, with benzyloxy being an exemplary arylalkoxy group.

All cited patents, patent applications, and other references areincorporated herein by reference in their entirety. However, if a termin the present application contradicts or conflicts with a term in theincorporated reference, the term from the present application takesprecedence over the conflicting term from the incorporated reference.

While typical embodiments have been set forth for the purpose ofillustration, the foregoing descriptions should not be deemed to be alimitation on the scope herein. Accordingly, various modifications,adaptations, and alternatives can occur to one skilled in the artwithout departing from the spirit and scope herein.

What is claimed is:
 1. An illuminating device, comprising: a lightsource; and a light-transmitting article formed from a thermoplasticcomposition, positioned to provide a light transmission path from thelight source through the light-transmitting article, with a distance, d,between the light source and the light-transmitting article of less than40 mm, the light transmission path extending through thelight-transmitting article and optionally through otherlight-transmitting article(s) comprising the thermoplastic compositionsuch that the total distance, p, of the light transmission path throughthe light-transmitting article is at least 3 mm; wherein thethermoplastic composition comprises a polycarbonate having repeatingstructural carbonate units according to the formula

in which at least 60 percent of the total number of R¹ groups containaromatic moieties and the balance thereof are aliphatic, alicyclic, oraromatic; the polycarbonate having been prepared through an interfacialpolymerization process from BPA monomer having an organic purity higherthan 99.70% by weight and having a hydroxyl content lower than 150 ppmby weight; 0.01 wt. % to 0.30 wt. %, based on the total weight of thethermoplastic composition, of an epoxy additive having at least twoepoxy groups per molecule; and 0.01 wt. % to 0.30 wt. %, based on thetotal weight of the thermoplastic composition, of a phenolic diphosphitederived from pentaerythritol; wherein the thermoplastic composition hasa sulfur content lower than 2 ppm; and wherein the thermoplasticcomposition exhibits a dE (2000 hrs.) value of less than 2.0 after 2000hours of heat aging at 130° C., measured according ISO11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mmthick molded plaque of the thermoplastic composition.
 2. Theilluminating device of claim 1, wherein p is at least 5 mm.
 3. Theilluminating device of claim 1, wherein d is less than 20 mm.
 4. Theilluminating device of claim 1, wherein d is less than 5 mm.
 5. Theilluminating device of claim 1, wherein the thermoplastic compositionexhibits the dE value of less than 1.50 after 2000 hours of heat agingat 130° C., measured according ISO 11664-4:2008(E)/CIE S 014-4/E:2007using CIE illuminant D65 and a 2.5 mm thick molded plaque of thethermoplastic composition.
 6. The illuminating device of claim 1,wherein the thermoplastic composition exhibits a b*<0.56 and a L*>95.65as measured according ISO 11664-4:2008(E)/CIE S 014-4/E:2007 using CIEilluminant D65 and a 2.5 mm thick molded plaque of the thermoplasticcomposition.
 7. The illuminating device of claim 1, wherein the epoxyadditive is an aliphatic epoxide having at least two epoxy groups permolecule and a molecular weight less than 600 g/mol.
 8. The illuminatingdevice of claim 1, wherein the epoxy additive is a carboxylate epoxyresin.
 9. The illuminating device of claim 8, wherein the epoxy additiveis a carboxylate epoxy resin comprising a carboxylate diepoxideaccording to the formula:


10. The illuminating device of claim 1, wherein the phenolic diphosphiteis according to the formula:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, and R₁₀ each independentlyrepresents hydrogen or a C₁₋₂₀ organic radical.
 11. The illuminatingdevice of claim 10, wherein R₂, R₅, R₅, R₇, R₉, and R₁₀ are H and R₁,R₂, R₆, and R₈ each independently represents a C₁₋₂₀ organic radical.12. The illuminating device of claim 10 wherein at least 40% of the R₁,R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, and R₁₀ groups are cumyl.
 13. Theilluminating device of claim 1, wherein at least 90% of the R¹ groupsare derived from the bisphenol.
 14. The illuminating device of claim 13,wherein all of the R¹ groups are derived from the bisphenol A.
 15. Theilluminating device of claim 1, wherein the thermoplastic compositioncomprises from 0.02 wt. % to 0.10 wt. % of the epoxy additive.
 16. Theilluminating device of claim 1, wherein the light-transmitting articleis an illuminant lens, illuminant cover, a light guide, or an opticalsheet.
 17. The illuminating device of claim 16, wherein thelight-transmitting article comprises a light guide wherein p is at least7 mm.
 18. The illuminating device of claim 1, wherein the illuminatingdevice is a display object, a toy, furniture, an art object, or a light.19. The illuminating device of claim 18, wherein the illuminating deviceis a motor vehicle headlamp.
 20. The illuminating device of claim 1,wherein the light-transmitting article comprises an aspheric lens. 21.The illuminating device of claim 1, wherein the light-transmittingarticle is a first lens along said light transmission path, and furthercomprising a second lens along said light transmission path further fromthe light source than the first lens, said second lens comprises thethermoplastic composition.
 22. The illuminating device of claim 1,wherein the light source is a light-emitting diode.
 23. The illuminatingdevice of claim 1, wherein the light source is a xenon arc lamp.
 24. Theilluminating device of claim 1, wherein the light-transmitting articlereaches a temperature between 80° C. and 135° C. during operation.
 25. Amethod of using the device of claim 1, comprising illuminating thelight-transmitting article with the light source under conditions tosubject the light-transmitting article to a temperature of 80° C. to135° C.
 26. A method for making the illuminating device, comprising:disposing a light source the distance d of less than 40 mm between thelight source and a light-transmitting article such that a lighttransmission path extending through the light-transmitting articlecomprising a thermoplastic composition and optionally through otherlight-transmitting article(s) comprising the thermoplastic composition atotal distance, p, is at least 3 mm; wherein the thermoplasticcomposition comprises a polycarbonate having repeating structuralcarbonate units according to the formula

in which at least 60 percent of the total number of R¹ groups containaromatic moieties and the balance thereof are aliphatic, alicyclic, oraromatic; the polycarbonate having been prepared through an interfacialpolymerization process from BPA monomer having an organic purity higherthan 99.70% by weight and having a hydroxyl content lower than 150 ppmby weight; 0.01 wt. % to 0.30 wt. %, based on the total weight of thethermoplastic composition, of an epoxy additive having at least twoepoxy groups per molecule; and 0.01 wt. % to 0.30 wt. %, based on thetotal weight of the thermoplastic composition, of a phenolic diphosphitederived from pentaerythritol; wherein the thermoplastic composition hasa sulfur content lower than 2 ppm; and wherein the thermoplasticcomposition exhibits a dE (2000 hrs.) value of less than 2.0 after 2000hours of heat aging at 130° C., measured according ISO11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mmthick molded plaque of the thermoplastic composition.